(PHP 5 >= 5.1.0, PHP 7)
Exception::getTrace — Gets the stack trace
Returns the Exception stack trace.
This function has no parameters.
Returns the Exception stack trace as an array.
Example #1 Exception::getTrace() example
<?php
function test() {
throw new Exception;
}
try {
test();
} catch(Exception $e) {
var_dump($e->getTrace());
}
?>
The above example will output something similar to:
array(1) {
[0]=>
array(4) {
["file"]=>
string(22) "/home/bjori/tmp/ex.php"
["line"]=>
int(7)
["function"]=>
string(4) "test"
["args"]=>
array(0) {
}
}
}
Two important points about this function which are not documented:
1) The trace does not include the file / line at which the exception is thrown; that entry is only recorded in the top-level getFile/Line methods.
2) Elements are returned in 'closest-first' order, e.g. if you have a script x which calls function y which calls function z which throws an exception, then the first trace element will be 'Y' and the second will be 'X'.
When calling getTrace(), there is also the name of the class in returned array:
<?php
class Test {
function __construct() {
throw new Exception('FATAL ERROR: bla bla...');
}
}
try {
$obj = new Test();
} catch(Exception $e) {
var_dump($e->getTrace());
}
?>
Will show something like:
array(1) {
[0]=> array(6) {
["file"]=> string(54) "/....../test.php"
["line"]=> int(37)
["function"]=> string(11) "__construct"
["class"]=> string(4) "Test"
["type"]=> string(2) "->"
["args"]=> array(0) { }
}
}
You can use this function to format a exception:
<?php
function MakePrettyException(Exception $e) {
$trace = $e->getTrace();
$result = 'Exception: "';
$result .= $e->getMessage();
$result .= '" @ ';
if($trace[0]['class'] != '') {
$result .= $trace[0]['class'];
$result .= '->';
}
$result .= $trace[0]['function'];
$result .= '();<br />';
return $result;
}
//Example:
try {
$obj = new Test();
} catch(Exception $e) {
echo MakePrettyException($e);
}
?>
Result:
Exception: "FATAL ERROR: bla bla..." @ Test->__construct();
The order of the trace starts at the source of the exception and does not include main.
So for example:
<?php
function Bar() {
throw new Exception;
}
function Foo() {
Bar();
}
try {
Foo();
} catch(Exception $e) {
var_dump($e->getTrace());
}
?>
Will output:
array(2) {
[0]=>
array(4) {
["file"]=>
string(21) "/.../test.php"
["line"]=>
int(8)
["function"]=>
string(3) "Bar"
["args"]=>
array(0) {
}
}
[1]=>
array(4) {
["file"]=>
string(21) "/.../test.php"
["line"]=>
int(12)
["function"]=>
string(3) "Foo"
["args"]=>
array(0) {
}
}
}
